<template>
    <div class="goodsinfo-container">
        <transition @before-enter="beforeEnter" @enter="enter" @after-enter="afterEnter">
            <div class="ball" v-show="ballFlag" ref="ball"></div>
        </transition>
        <!-- 商品轮播图区域 -->
        <div class="mui-card">
			<div class="mui-card-content">
			    <div class="mui-card-content-inner">
					<swiper :swipeList="lunbotu" :isfull="false"></swiper>
				</div>
			</div>
		</div>
        <!-- 商品购买区域 -->
        <div class="mui-card">
			<div class="mui-card-header">{{ goodsinfo.title }}</div>
			<div class="mui-card-content">
				<div class="mui-card-content-inner">
					<p class="price">
                        市场价：<del>￥{{ goodsinfo.market_price }}</del>&nbsp;&nbsp;销售价：<span class="now_price">
                            ￥{{ goodsinfo.sell_price }}</span>
                    </p>
                    <p>购买数量：<numbox @getCount="getSelectedCount" :max="goodsinfo.stock_quantity"></numbox></p>
                    <p>
                        <mt-button type="primary" size="small">立即购买</mt-button>
                        <mt-button type="danger" size="small" @click="addToShopcar">加入购物车</mt-button>
                    </p>
				</div>
			</div>
		</div>
        <!-- 商品参数区域 -->
        <div class="mui-card">
			<div class="mui-card-header">商品参数</div>
			<div class="mui-card-content">
				<div class="mui-card-content-inner">
					<p>商品货号：{{ goodsinfo.goods_no }}</p>
                    <p>库存情况：{{ goodsinfo.stock_quantity }}件</p>
                    <p>上架时间：{{ goodsinfo.add_time|dateFormat }}</p>
				</div>
			</div>
			<div class="mui-card-footer">
                <mt-button type="primary" size="large" plain @click="goDesc(id)">图文介绍</mt-button>
                <mt-button type="danger" size="large" plain @click="goComment(id)">商品评论</mt-button>
            </div>
		</div>
    </div>
</template>
<script>
import swiper from '../subcomponent/swiper.vue'
import numbox from '../subcomponent/goodsinfo_numberbox.vue'
export default {
    data(){
        return {
            id:this.$route.params.id,  //将路由参数对象中的id挂载到data，方便后期调用
            lunbotu:[],
            goodsinfo:{},
            ballFlag:false,  //控制小球隐藏和显示的标识符
            selectedCount:1
        }
    },
    created(){
        this.getLunbotu();
        this.getGoodsInfo();
    },
    methods:{
        getLunbotu(){
            this.$http.get('api/getthumimages/'+this.id).then(result=>{
                if(result.body.status===0){
                    //先循环轮播图数组的每一项，为item添加img属性，因为轮播图组件中只认识item.img，不认识item.src
                    result.body.message.forEach(item=>{
                        item.img=item.src;
                    })
                    this.lunbotu=result.body.message;
                }
            })
        },
        getGoodsInfo(){
            this.$http.get('api/goods/getinfo/'+this.id).then(result=>{
                if(result.body.status===0){
                    this.goodsinfo=result.body.message[0];
                }
            })
        },
        goDesc(id){
            this.$router.push({name:"goodsdesc",params:{ id }});
        },
        goComment(id){
            this.$router.push({name:"goodscomment",params:{ id }});
        },
        addToShopcar(){
            this.ballFlag=!this.ballFlag;
            //拼接出一个要保存到store中car数组里的商品信息对象
            var goodsinfo={
                id:this.id,
                count:this.selectedCount,
                price:this.goodsinfo.sell_price,
                selected:true 
                }
            this.$store.commit('addToCar',goodsinfo)  //调用store中的mutations来将商品加入购物车
        },
        beforeEnter(el){
            el.style.transform="translate(0,0)"
        },
        enter(el,done){
            el.offsetWidth;
            //小球动画优化思路
            //1.先分析导致动画不准确的本质原因，我们把小球最终位移的位置，已经局限在了某一分辨率下的滚动条未滚动的情况下；
            //2.只要分辨率和测试的时候不一样，或者滚动条有一定的滚动距离之后，问题就出现了
            //3.因此，经过分析，不能把位置的横纵坐标直接写死了，而是应该根据不同情况，动态计算这个坐标值；
            //4.经过分析，得出解决思路，先得到徽标的横纵坐标，再得到小球的横纵坐标，然后让y值求差，x值也求差，得到的结果就是横纵坐标要位移
            //的距离
            //5.如何获取徽标和小球的位置？domObject.getBoundingClientRect()
            //获取小球在页面中的位置
            const ballPosition=this.$refs.ball.getBoundingClientRect();
            //获取徽标在页面中的位置
            const badgePosition=document.getElementById('badge').getBoundingClientRect();
            const xDist=badgePosition.left-ballPosition.left;
            const yDist=badgePosition.top-ballPosition.top;
            el.style.transform=`translate(${xDist}px,${yDist}px)`;
            el.style.transition='all 0.5s cubic-bezier(.4,-0.3,1,.68)';
            done()
        },
        afterEnter(el){
            this.ballFlag=!this.ballFlag;
        },
        getSelectedCount(count){
            //当子组件把选中的数量传递给父组件的时候，把选中的值保存到data上
            this.selectedCount=count;
        }
    },
    components:{
        swiper,
        numbox
    }
}
</script>
<style lang="scss" scoped>
    .goodsinfo-container{
        background-color: #eee;
        overflow:hidden;
        .now_price{
            color: red;
            font-size: 16px;
            font-weight: bold;
        }
        .mui-card-footer{
            display: block;
            button{
                margin:15px 0;
            }
        }
        .ball{
            width:15px;
            height:15px;
            border-radius: 50%;
            background-color: red;
            position: absolute;
            z-index:99;
            top:390px;
            left:146px;
        }
    }
</style>